On the Dynamics of Wind-Driven Circumpolar Currents
On the Dynamics of Wind-Driven Circumpolar Currents
复制标题
风驱动绕极流动力学
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
D. Marshall
中科院分区：
文献类型：
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作者：
C. E. Tansley;D. Marshall
南极绕极流（ACC）输送的控制因素是近年来人们争论的热点。在德雷克海峡的纬度，位涡轮廓是不间断的海岸线，大振幅的流动是可能的，即使有弱的强迫和耗散。本文讨论了环极流动力学与封闭海盆惯性再循环之间的关系。在以往的研究中，Sverdrup平衡理论和斜压调整理论都被认为是ACC输送的理论。这些理论将绕极输送预测为地面风应力的各种简单函数。一系列的实验进行了一个简单的通道模型，不同的风强度和不同的理想化的盆地的几何形状，研究风强度和绕极输送之间的关系。结果表明，斜压调整理论在没有地形变化的周期性通道的特殊情况下，或当风强迫很弱时，可以预测输送。更一般地说，运输是由风强迫，涡通量和地形效应之间的复杂的相互作用。没有证据支持斯维尔德鲁普平衡决定了德雷克海峡的输运。
The factors controlling the transport of the Antarctic Circumpolar Current (ACC) have recently been a topic of heated debate. At the latitudes of Drake Passage, potential vorticity contours are uninterrupted by coastlines, and large amplitude flows are possible even with weak forcing and dissipation. The relationship between the dynamics of circumpolar currents and inertial recirculations in closed basins is discussed. In previous studies, Sverdrup balance and baroclinic adjustment theories have both been proposed as theories of the ACC transport. These theories predict the circumpolar transport as various simple functions of the surface wind stress. A series of experiments is performed with a simple channel model, with different wind strengths and different idealized basin geometries, to investigate the relationship between wind strength and circumpolar transport. The results show that baroclinic adjustment theories do predict transport in the special case of a periodic channel with no topographic variations, or when the wind forcing is very weak. More generally, the transport is determined by a complex interplay between wind forcing, eddy fluxes, and topographic effects. There is no support for the idea that Sverdrup balance determines the transport through Drake Passage.